Background: The overall cost of CKD accounts for 1.3% of health care budgets of which 13% is related to the excess myocardial infarctions and strokes associated with CKD. Objective: To assess the effect of native vitamin D supplementation in high doses on cardiac functions in hemodialysis (HD) patients. Patients and Methods: This was a prospective cohort study which done in Kobry Elkobba Military Hospital conducted from June to September 2020 on 50 regular hemodialysis patients for > 6 months; to assess the effect of native vitamin D supplementation in high doses on cardiac functions in hemodialysis (HD) patients. Results: Multiple regression analysis showed that after applying (Forward method) and entering some predictor variables the increase in baseline TGs; and the decrease in vitamin D level; had an independent effect on increasing follow-up (3-months) LVMI; with significant statistical difference (p < 0.05 respectively). Logistic regression analysis shows that; after applying (Forward method) and entering some predictor variables; the increase in Vitamin D level; had an independent effect on increasing the probability of EF improvement occurrence; with significant statistical difference (p = 0.0005). Conclusion: Vitamin D played a pivotal role in uremic CVD and its supplementation should be considered even in the absence of mineral metabolism disorders, after hypovitaminosis is detected.